The excretory duct of the Wolffian body (fig. 401. e) is converted into the canal of the epididymis, (fig. 402. e), and ultimately into the vas deferens, and whilst the retro gression and final obliteration of the terminal part of this duct takes place normally in the female, (fig. 403. e) it constitutes a patho logical condition when it occurs in the male. The terminal bulb (fig. 401. i) of the duct of Miiller is converted into the hydatid of Mor gagni (fig. 402. i), whilst its inferior por tion (fig. 401. h) still exists, at a later period in the anterior border of the epidi dymis (A. 402.h).
Tracing the development of the c9rre sponding structures from the same point of departure as in the male, we find that in the female, also, the \Vona!' body never dis appears entirely, but is employed in the for mation of the parovarium. Its middle blind pouches (fig. 401. c c), are converted into the 18-20 tubules of the parovarium (fig. 403. c), and these secerning tubes become organi cally connected with the hilum of the ovary, /. They are the homotypes of the male coni vasculosi, and vasa effcrentia, but which con stitute here vasa adferentia.
The superior blind pouches and the bulb of the excretory duct disappear, or contri bute to form the hydatids at the outer border of the parovarium (fig. 103. f b), which are so commonly mistaken for morbid struc tures.
The inferior blind pouches (fig. 401. d) remain and represent the vasa aberrantia of Haller (fig. 402. d), in the male. Several of them become elongated and intermingled with the vessels of the spermatic plexus (fig. 403. d).
The excretory' duct of the Wolffian body (fig. 401. e) in the female, undergoes a retro gression in its whole length, and the lower end disappears entirely. (Fig. 403. e).
The duct of Milner (fig. 401, h) is con verted into the Fallopian tube (fig. 403. h), and its bulb ( fig. 401. i) becomes the terminal hydatid of the same (fig,.403. i). This latter structure, of which a very excellent example, as occurring on both sides, is given infig.368. e e, is very constantly present in the adult. Like the so-called hydatid (fig. 403.fand 408. g) at the outer border of the parovarium, it is frequently mistaken for a morbid product, and. is often so designated in descriptions of these parts ; an error which the improper title of hydatid tends to propagate.
The interruption or deficiency of the Fal lopian tube in the female is a malformation, which represents a nortnal condition in the male.
The parovarium exhibits parallel stages of development and retrogression with its corre sponding ovary at different periods of life.
Abnormal Anatomy of the Parovarium. — So little attention has been given to this structure in its natural condition that accu rate information regarding its morbid states can hardly be looked for. The so-called hydatids, which are found at the outer bor der of the parovariutn in most adult speci mens, and which are constructed ont of the superior blind pouches and bulb of the ex cretory duct of the Wolffian body, have been already just noticed as normal structures. These are found pretty constantly in younger subjects, while the hydatids of later fornia tion in the vespertilionum are formed of the remains of the canals of the retrograde parovarium. Within the walls of these canals is collected occasionally a considerable amount of fluid, and it is probable that this is the origin of those larger accumulations to which the term dropsy of the broad ligament has been applied.